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-rw-r--r-- | doc/todo/make_copy_--fast__faster/comment_3_5cd9e6b5d6d015120b5852bd212314aa._comment | 22 |
1 files changed, 22 insertions, 0 deletions
diff --git a/doc/todo/make_copy_--fast__faster/comment_3_5cd9e6b5d6d015120b5852bd212314aa._comment b/doc/todo/make_copy_--fast__faster/comment_3_5cd9e6b5d6d015120b5852bd212314aa._comment new file mode 100644 index 000000000..d4aa80ecb --- /dev/null +++ b/doc/todo/make_copy_--fast__faster/comment_3_5cd9e6b5d6d015120b5852bd212314aa._comment @@ -0,0 +1,22 @@ +[[!comment format=mdwn + username="joey" + subject="""comment 3""" + date="2016-05-31T16:02:01Z" + content=""" +copy --to has to query the git-annex branch to see if the file is on the remote. +So it has worse locality than copy --from, which can simply stat the local +file to see if it's present. + +Whatever inneficiencies git-annex has here are well swamped by the overhead +of git querying the branch. + +When the remote has most of the files already, `git annex copy --to remote` is +similar to `git annex find --not --in remote`. + +Here I've ran that under /usr/bin/time, and it looks like git-annex +ran for 89 seconds out of the 260 second runtime. So at least 65% of the total +runtime is spent by git querying the branch. + + 89.26user 6.92system 4:20.80elapsed 36%CPU (0avgtext+0avgdata 75584maxresident)k + 516432inputs+0outputs (0major+31156minor)pagefaults 0swaps +"""]] |